Production of sounds



M. MAAG PRODUCTION OF SOUNDS Fil d Dec. so. 1622 z Sheets-Sheet 1 Inventor flaw/Vang z wazgf Aug. 21, 1928. 1,681,546

M. MAAG PRODUCTION OF sounns Filed Dec. 30. 1922 2 Sheets-Sheet 2 'I'Id'llllllll'll'l'tll llllllll'llll I Inventor:

f asc Haas? B, A (m,

Patented Aug. 21, 1928.

max MAiAG- onscHwA-Mnnnmenn, NEAR'LZ'URICH," swrrznnnnnn.

PRODUCTION. on SOUNDS;

Application filedgDecember 30, 1922,' Se'ri'a1 Hi 610,076:amiiinrfibrmany December. 31, 1921;

My invention relates to. a new device ormeansffor producing sounds with the, aid.

of. what may be termed sounding curves.

It? is known that by. blowing towards and 1 upon a moving disk, ring or band, having;

its, edg e or'edges shaped to conform toa sounding curve, sound can; be produced corresponding to the-particular'shape of the saidisounding curve .(wave siren).

Therobject of my invention is toprovide' a soundproducer' constructed in accordance wlth the above; lndlcated idea or principle. To thise end my invention provides means for. producing sounds, in a sounding tube,v

preierabl of funnel-shape, into which air isblown ori sucked and. which at one of its ends.- terminatesin a mouth or opening located, in front ofthe sounding curve carrier (-band, wheel, or the like), while its a other end opens freely into the atmosphere.

Throughthe latter endof the sounding tube,

therefore, aportion of the blowing air is allowed. to flow. out, the amount of said portion depending upon andv corresponding to the degree to which the aforesaid mouth of the. tubeis closed or: covered by the sounding curve band or WheeLt-hatis to say the more the said band or. wheel actsto close or occlude themouth or passage, the more,

air is caused totake its way out through that end of the tube which immediately opens into the atmosphere. The portion of theblown or sucked in air thus escaping directly, into theatmosphere and forming. what maybe termedthe I'QHCtTODrfiiIf, s adaptedto produce: in ,the sounding tube air pushes or pulsationswhich result in the" production of sounds. Herein ITGSlClGS'tlldBSSQDtlfll feature otmyinvention.

As an advantage body, wheel or; band, can be movedin front of and. over the blowing mouth of the tube in closest proximitythereotso as to pra ctically close the same at lntervals. This 1s so the blowing air is free to escape even incaserof a complete closure at the mouth from the opening, at. the; other end. of the tube and thus any disturbing reaction in the blowing device resultingin variations of; pres- 1 suioand. sound cannot be produced. Conse quently a relatively moderate expenditure. of air,- is. ensured. and stillha. very. perfect andexact reproductionof: the single sounds of the sounding, curve. coactmg to compose thetonality acoustic; character. or tiinbre,is.

thereof the sounding? obtained, mainly :ow-ing: to :the'..s trict limitaetion of thecurrent or flow: of air forced. through "the mouth: of; the 5 tube" locatedi in; v

close proximity to the curve-rimmed sound ing'band or wheel, a

In the; accompanying drawing. I have: shown several-embodiments ofz'my. invention.; In t the drawing Figure; 1 is a: side elevation;

of, the sounding-device or apparatus; partly? in section, Figure 2-.isI at'plan; thereof: withi certain parts broken. off," Figuresfi. and g4 are. two different views of a portion-.- thereof,. Figures 5: to. 7- aresectional views; illustrat,- ing certain details of: modified? construction, Figures 8 and; 9; are perspective views-off modifications of? the prineipalj parts of, the; device and; Figures. 1.0 to. 1% are another modification, shown; inseveral; sections and; views.

Referring; to Figs.- 1 and. 2 a rofllrl? driven; by anysuitable means (not shown); to' rotate at auniforma speed, carriesa ribbon: or band; 2 adapted; tounwind from. a: roll 3V and: to be wound, upon 3,31'011'4, The; band 2 is provided. with; or. shaped to form undulatony or: dentiform projections or; laps at one otits-longitudinal. edges,asinl ig. 3,;or a tz both edges as inFigVQZ In the} latter case the said projections or lapsare shaped and: located symmetrically; with re gard tothe longitudinal median line; ofthe hand. These projections and the gaps or-- recesses therebetween representin either; case; I

complements ot the; sounding curve to. be; reproduced.

closerproximity of theband 2. The, mouth 6 of the tubev is slot-shapedor enlarged, as.

will be clearly; seen in Figs. 2.and '3,.to;-ex-

tend over the whole w-idthof the-band. The

' v Diametricallyl opposite therollla sound mg tube 5 is mounted with its mouth oiinr valve 9 and has an extension; 10 connectedw with. a, blower 1-1 of? any convenient type.-

Assuming;the;valve9 s open. and aisle;

forced into the tube 5, the forced in air will take its way, as indicated by the two arrows in Fig. 1, in two directions, that is to say, towards the two ends of the tube 5. Further assuming the band 2 is caused to move with a' uniform speed over the periphery of the roll 1, now when awider or lapped portion of the band passes below the mouth 6, the latter -will be closed by the band more or less and a correspondingly increased or reduced amount of the air injected by the pipe 8 will take its way towards the free end, of the tube 5 opening into the atmosphere. In the two limitcases, that is where the lapped band 2 covers and closes the mouth 6 to its full width and where the width of the .band is practically equal to zero, as shown in Fig; 3, the whole volume of air injected at that moment into the tube 5 will, in the, former case, be forced out therefrom through the funnel-shaped free end of thetube, whereas, in the latter case, about one half of the injected air will flow towards the funnel- =shaped end of the tube 5, while the other half thereof will pass through the mouth 6.

If, therefore, the band 2 is shaped and lapped in a manner that portions of largest width follow each other in succession with marrow sized portions intermediate between each two lapped portions, more or less air will be forced, in'corresponding alternation. towards and through the funnel-shaped end of the tube 5, and a pulsatory air current will be produced therein. Obviously the pulsations ofsucha current occur and are in strict accordance or time with the laps of the band 2 passing the mouth 6, said pul-j 1 vibratory range of audible sounds.

The expenditure of pressure air may be reduced and still the efficiency will be increased by producing very vigorous pulsations in the sounding tubef For this purpose the device or apparatus may be constructed and arranged in a manner that the air current passing from the supply pipe 8 over into the sounding tube 5 will be adapted to produce not only more orless considerable compressions of the air in the tube, but also 'rarefaction's or vacua therein.

Aronstruction of the kind is shown in Fig. 5, wherein the supply'pipe 8 is attached to the tube 5 at an acute angle, so that the current of air forced in by the former acts in the manner of an ejector to push the air contained in the tube 5 out towards and through the mouth 6. Consequently if the mouth 6 is free and not closed or Covered, no air will flow towards the shown in Figs. 6 and funnel-shaped end of the tube 5, on the contrary, the air contained therein will be sucked out and rarifiedand a current of air will flow therefrom towards and through the mouth 6. If, however, the mouth 6 is covered or closed, the current of air forced in by the pipe 8 will, without any division, in its totality escape through the funnelshaped end 7 of the tube 5. Hence the alternation in partly or totally closing and opening the mouth 6, therefore, will result in producing more powerful pulsations in a construction, as shown in Fig. 5, and more vigorous sounds will be obtained than by the construction illustrated in Fig. 1. i

In the embodiment of my invention 4 8 is located within the sounding tube'5 and its downwardly eirtendingend 12 is fiattened out to form a flaring slot a little above and in conformity with the mouth 6 of the tube 5. By this construction the air is sucked out from the tube 5 in a very powerful manner, when the mouth 6 is uncovered. Also in this modification all the air coming from the supply pipe 8 will be adjusting the vertical position of the air supply pipe 8 with relation to the tube 5 or mouth 6 the sucking efiiciency can be con--- mo trolled and regulated.

The device described'in' the foregoing, especially the apparatus as shown in F ig. 1 containing the sounding curve on a band of corresponding length is primarily adapted to reproduce musical and talking pieces of greaterlength, in particular for a wide range and variety of successive sounds.

But my invention is likewise capable of' reproducing tunes of an invariable number of oscillations and invariable sounding character, therefore for tones adapted for the construction of organ-like instruments. In this case the sounding curvesare-preferably arranged as cylindrical rings, as shown in Figs. 8 and 9.

A ring of this kind comprises a shaft 13 with radial arms or spokes and a rim 14:, the whole forming a kind of a wheel. the construction shown in Fig. 8 the rim is shaped by cutting, punching, etching or in any other suitable manner to form two lapped rings with the laps or teeth opposed to each other, so that the gap therebetween has a form and contour similar to that of the band 2 shown in Fig. 2 and representing what may be termed the sounding curve. In the modification illustrated in Fig. 9, however, the ring itself is shaped at its edges to form the sounding curve and similar to the band 2 in Fig. 2, as regards its contour.

the air supply pipe.

in? both embodiments, Figs. 8 and 9, the sounding curve is movedby the. rotation ofthe shaft 13,to' pass below the mouth of the sounding tube and, in doing so, caused to throttle the air current emanating from said mouth, more or less in accordance with. the shape- 0fthe point of the curve just below the mouth, whereby the sound. producing pulsations or pushes of the air are brought about I 7 Further, the sounding curves may be formed at: the edge. of discs rotating about their aizles like a wave'siren, an air stream.

being blown against thetoothededge. Instead of the sounding curves being formed asdescribed above holes of a proper shape maybe punched into a disc or a ring, the holes being arranged on a circleconcentric to the rotating axle.

" in-adevice of such kindis not made of a oflthe reaction impulses.

Such device is shown in Figs. 10 to 1 Fig. 10 showing a cross-section through the sounding curve carrler'being shaped llke a siren disc, the blowmg mouth and the resonator, Fig. 11 showinga side-view and Fig.

12 an elevationppartly in section. Fig. 13

shows the blowing mouth in a larger scale,

and Fig. ll a simplified modification.

Referring to Figs. 10 t0 13 a disc 15.fixed lo a shaft 15. has concentrical. positioned l1oles16 of a triangular shape and is rotated with uniform velocity. holes on the concentric circle in which they are arranged is equal to the-distance of two'adjaeent holes. The radial extension is of no importance. A blowing'mouth 17 is vertically directed against the, disc and opposite to the circle of the holes 16, the

said blowing mouth consisting inna box;

18 containing a blowing pipe 19 connected bya pipe 20- to a'blower (not shown). In the pipe 19 is fixed by stems 23, 23 a needle 21 otsuch shape that the air stream escaping fromthe pipe19 is divided and pressed outwardly. against. the mouth of a suctionpipe 24 into the. sucti0nchamber 22, in order to increase the suction effect. The mouth of the box lS'has thesame 'shape-asthe holes 1-6. This shape is so that on the disc 15 being rotated airthrusts are brought about in the reaction chamber 22, the

The blowin mouth The extension oi. the

strength of whieh begins: with a maximum on the mouth 17: being. closedgbyetheadisc,

then becomes. weaker; in. sinus: f0lim. ,0l11 the said mouth being more: and. more set; free;

by: a hole 16,. going; throughnought tonal minimum, which is reachediwhen theunouth is fully set free and theninoreases againp when the mouth beingmorerandmore+clbsedz by the rotating disc, through nought'toama xi- 'n1um,. always following; the si-n.e curve.

The IQiLCtlOILCllEHnbGI 221s; connected by; a-plpe 24 to. a resonator 25,,theosc1llat1on proper of which is tuned tothe-frequencya,;

of the air thrusts of the reaction im pulsea thesaid frequency being equal to the;.procl not of the number of the holeslii witli disc 15. i y v Preferably the air stream on the back side of the :disc is not allowed to blow outin the free air but is caught byfimoutlr piece-26: an-dled by a pipe 27 into thepresonatorw2.

the number ofrotationsperrseeond offthe- Thereby the said impulseis freefrom: all

disturbing noises and arrives a-t 't'he resonator as an mpulse of pure- S1116 form, in.

creasing the reaction impulse." Toe'secure."

this result. it is necessary that the lengths of the two leading pipes: 24. and 2.7 differ from each other by an oddsnumber-of hEl-lf'fl'q' wave length of the tone to be produced:

This is due to the fact that the. two impulses;.,

the reaction impulse and the? siren-impulse oscillate in opposite phase, so. that anzair compression takes place in; the mouthpiegze 26 while there 1s a rarefaetion in the reaction:-

space 22 andvicerversa. ,Tli'erefore-thmtwo in'mulses-lead into the resonator by leading tubes of equal length would arrivethere'in opposite phase, the effect ofiwhich would not bea reinforcement of theoscillation but aweakening'of it. In order to get the desired: reinforcement it will be necessary thatit-he.

two impulses arrive in. the. resonator; in".

equal phase,- This-may bereach'ed :byya diff ference in length of the two leading pipes equal to one-half wave length of the tone to be produced or of any oddinultipleoflit as two ad acentsnodes' of any oscillationare in opposite phase and at a distance of half: a wave length.

It is of no importance whateven',which Inf the leading .pipesbe the longer one. Also it is of little importance how long the one is:

made. A certain profit in loudness may, be

gained, however, if the length otthe one leading pipe is madeequal .to halt a' wave; I length of ,the tone to be produced or an=odd'-- multiple of it, as m" this case-"a standing- Y wave is produced whicharesults in a;1'ein forcement of the impulse.

being introduced individually into' 'the*reso-;

nator,-=be combined with each, other: in'the' followingway: the sirenimpulse maybe I ledby a pipe of the-length of onc half ware-- 1-25:;.-. The two pipes, 24:: and 27 may, instead otlength or an odd multiple of it of the tune to be produced into the reaction chamber and therefrom, together with the reaction impulse, a common pipe to the said resob .IIatOIZ guch device is shown in Fig. 14:, in

which 28 is the described pipe leading the siren impulse to the reaction chamber 22, and 29 the pipe common to both impulses and leading then to the resonator 25. The length of the pipe 28 must be, as explained, equal to one-half of a wave length, or equal to an odd multiple of one-half wave length,

the length of the pipe ,29 being of little imortance as explained above.

Obviously'the reaction impulse could be led from the chamber 22 into the mouth 26 and therefrom, together with the siren impulse, into the resonator25.

It is obvious that in lieu of a blower, such as 11, sucking devices of appropriate kind may be employed in connection with the described new apparatus, since by sucking off the air from the sounding tube 5 through the pipe 8 more or less powerful pulsations orrushes of air are produced, by the agency of be of the proper size and relationship, and

will be properly mounted and supported in accordance withthe tenets of machine construction; nor have I attempted to illustrate the parts in their'exact sizes and dimensions as many of 'the parts are conventionally shown. I I

While I have diagrammatically shown and described a few specific constructions it is obvious that the devices shown can be modified without departing from the spirit and scope of my invention.

What I claim as my invention is 1.- A sound producing device comprising a sounding tube having a sounding end freely open to the air and a sound producing end, means 'co-operating with the said sound producing end to close the same more or less, an air pipe connected with the said tube to open thereinto adjacent to the sound producing end, a device in connection with said air. pipe and adapted to force therethrough a current of air toward the pulsations producing end, means permitting said current to escape simultaneously through said tone producing and pulsation producing end,and means for controlling the operation of the said device, essentially as and A for the purpose set forth.

2. A sound producing device comprising a sounding tube having a sounding end freely open to the air and an air pulsations producing end, a figurate band'movable to co-operate with the latter to close the same more or less, an air pipe connected with the said tube and opening thereinto adjacent to the said narrower end thereof, a device in connection with said air pipe and adapted to cause a current of air to move therethrough toward the pulsations producing end, means permitting said current to V escape simultaneously through said tone producing and pulsation producing end, and

means for controlling the operations of the said device, essentially as and for the pur-' thereof, a device in connection with said air pipe and adapted to cause a current of air to move therethrough toward the pulsations producing end, means permitting said current to escape simultaneously through said tone producing and pulsation producing end, and nieans for controlling the operation of the said device, essentially as and for the purpose set forth. 7

4. A sound producing a sounding tube having a wider sounding end andv a narrower air pulsations producing end, means co-operating with the last stated tube end to close the same more or less, an air pipe attached to the said tube at an acute angle adjacent to the narrower end thereof, a device in connection with said air pipe and adapted to force therethrough a current ofair', and means for controlling the operation of the said device toward the pulsations producing end, means permitting said current to escape simultaneously through said tone producing and pulsation producing end, essentially as and for the purpose set forth.

5. A sound producing device comprising a device comprising sounding tube having a sounding end and an air pulsations producing end, a figurate band movable to co-operate with the latter to closethe same more or less, an air pipe attached to the said tube at an acute angle adjacent to the narrower end thereof, a device in connection with said air pipe and adapted to cause a current of air to move therethrough toward the pulsations producing end, means permitting said current to escape simultaneously through said tone producing and pulsation producing end, and

means for controlling the operation of the said device, essentially as and for the purpose set forth.

6. A sound producing device comprising in combination a sounding tube having a sounding end and a slot-shaped air pulsations producing mouth, a figurate band movable to co-operate with.the latter to close the same more or less, an air pipe adjus'tably inserted in the said tube with its inner end in co-axial relationship thereto and with its flaring slot-shaped mouth in alignment with the slot-shaped mouth of the sounding rent to escape simultaneously through said 7 tone producing and pulsation producing end, and means for controlling the operation of the said device, essentially'as and for the purpose set forth.

In witness whereof I have hereunto signed my name this 7th day of December, 1922.

MAX MAAGQ 

